const base64ToBlob=(data:any)=> {
    var arr = data.split(','),
        mime = arr[0].match(/:(.*?);/)[1],
        bstr = atob(arr[1]),
        n = bstr.length,
        u8arr = new Uint8Array(n);
 
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n);
    }
    return new Blob([u8arr], { type: mime });
}
 
export const CompressImage:any=(src:any,width:number)=> {

return new Promise((resolve)=>{

    const img = new Image();
    img.src = src;
 
    let cvs = document.createElement("canvas");
 
    img.onload = function () {
        let ratio = img.naturalWidth / img.naturalHeight; //  获取原图比例,为了等比压缩
        cvs.width =width;
        cvs.height = cvs.width / ratio;
        let ctx:any = cvs.getContext('2d');
        ctx.drawImage(img, 0, 0, cvs.width, cvs.height);    //  画在 canvas 上

        ctx.font = "40px Arial";
        ctx.fillStyle = "white";
        ctx.fillText("乐柠", 50, 50);
        // 压缩后新图的 base64
        let zipBase64 =base64ToBlob(cvs.toDataURL());
        resolve(zipBase64);
        
    }

 })
    
}